1. Field of the Invention
The present invention relates to a strain waveform control apparatus adapted to support a strain waveform regulating member to bring it into contact with a proper place of a fixedly-supported specimen and generate strain waveforms by applying an impact to the specimen and then control (modify and adjust) strain waveforms, and further relates to the strain waveform regulating member, a strain waveform control method by using the strain waveform control apparatus and a strain waveform control program. In particular, the present invention relates to a strength evaluation using an impact test device (inclusive of a destructive test device) by generating any strains on a printed circuit board in the neighborhood of a micro junction part such as a solder junction part formed in an electronic component and a conductive pattern adhesion part formed on its circuit board, respectively.
2. Description of the Related Art
The conventional impact test device is configured to generate strains on a printed circuit board fixed in place by applying an impact force thereto. The strain waveforms generated on the printed circuit board are determined by an initial impact force and/or a fixing position for the printed circuit board. The impact test device is also configured to control a vibration appearing on the strain waveforms by changing the impact force and particularly to limit an object to be controlled only to an initially generated strain.
For example, in Japanese Laid-Open patent publication No. 62-298739, there is described a apparatus adapted to verify an integrity of a solder joint part between a lead line of a IC-package and a printed wiring on a IC-package mounted printed circuit board.
However, even if a test of a printed circuit board is performed by externally application of an impact force thereto on the condition that the printed circuit board is simply fixed in place, it is often difficult to regard the printed circuit board as a final product and evaluate it because the result obtained from such a test (for example, a damping factor of a strain peak is generally apt to be constant) is different from that obtained when the printed circuit board has actually been built in a box-like body, e.g., an outer casing, as the final product. Therefore, even if the impact test is performed in a state as possible as near to a final product, it is disadvantageously impossible for the conventional impact test device to control a shape(s) of a strain waveform(s) (particularly, first and second occurred waveforms) generated by a damping vibration occurred with the impact into a desired shape(s). For example, when a bigger impact is applied to a specimen in order to prevent a peak of the second occurred waveform from being lessened so much, only a peak of the first occurred waveform (the maximum strain waveform peak) is enlarged because of the phenomenon that the specimen will expand depending on the impact without much change in the second occurred waveform peak. Accordingly, it is disadvantageously often difficult to enlarge relatively the second occurred strain waveform peak than the first occurred strain waveform peak by using the same specimen. On the contrary, when it is intended to lessen only the second occurred strain waveform peak relatively in comparison with the first occurred strain waveform peak, the first occurred strain waveform peak is also lessened in addition to the second occurred strain waveform peak. Thus, it is disadvantageously often difficult to lessen only the second occurred strain waveform peak.